There have been various rumors about more prequels and sequels, as there always are, but nothing concrete until this new TV series now in development for FX on Hulu.
Alien has had four movies, two prequels, and two crossover movies with the Predator franchise.
Note that the series is one of the FX series made specifically and exclusively for Hulu.
It’s had comic books, novels, video games, toys, merchandising, and probably a breakfast cereal or two along the way.